Adicionando uma cor de fundo transparente em CSS
div {
background-color: #b2b2b2;
background-color: rgba(0, 0, 0, .3);
}
Hatim Eddinani
div {
background-color: #b2b2b2;
background-color: rgba(0, 0, 0, .3);
}div {
background: transparent
}body {
background-color: rgb(255,255,255);
}.opacity30 {
opacity: 0.3;
filter: alpha(opacity=30); /* For IE8 and earlier */
}div {
opacity:25% ;
}background:transparent;